chest pain

well my name is whitney and i am 16.See i have a little problem when i was younger i had a heart murmur and i had surgery when i was about 6 or 7 months.When i was little i use to go to the doctor for a reguarly check-ups to make sure everything was ok and after i was 5 i stop doing reguarly check-ups cause said i was fine.Now for the past year every once in a while i would get these bad chest pains for like a minute and i barely have any engery i use to play sports now i can't play sports cause its hard for me to breath. I don't know what is going on with me but i don't feel like my self anymore is there anyone that can help me?